Yes charge backs have very strict rules. One for merchants is that any refunds of a charge must go back on the same charge account.
A former customer of mine bought a $4,500.00 ring on her Visa Card. She returned it and wanted the refund in cash. I informed her that it was against Visa's rules and I would have to refund it to her card. She got highly incensed and told me that her bank allowed it and she did it all the time and she was going to complain to them. I let her know that I would contact Visa and double check with them. I did and as I knew and expected they would not allow it. The woman was committing fraud. Her card gave her points for travel and getting a cash refund allowed her to keep points she was not entitled to. This was stealing even though in her mind it wasn't.